Faculty Bibliography

INTRODUCTION/BACKGROUND:Selective use of dual mobility (DM) implants in total hip arthroplasty (THA) patients at high dislocation risk has been proposed. However, evidence-based utilization thresholds have not been defined. We explored whether surgeon-specific rates of DM utilization correlate with rates of readmission and reoperation for dislocation. METHODS:We retrospectively reviewed 14,818 primary THA procedures performed at a single institution between 2011 and 2021, including 14,310 FB and 508 DM implant constructs. Outcomes including 90-day readmissions and reoperations were compared between patients who had fixed-bearing (FB) and DM implants. Cases were then stratified into three groups based on the attending surgeon's rate of DM utilization (≤1, 1 to 10, or >10%) and outcomes were compared. RESULTS:There were no differences in 90-day outcomes between FB and DM implant groups. Surgeon frequency of DM utilization ranged from 0 to 43%. There were 48 surgeons (73%) who used DM in ≤ 1% of cases, 11 (17%) in 1 to 10% of cases, and 7 (10%) in >10% of cases. The 90-day rates of readmission (7.3 vs 7.6 vs 7.2%, P=0.7) and reoperation (3.4 vs 3.9 vs 3.8%, P=0.3), as well as readmission for instability (0.5 vs 0.6 vs 0.8%, P=0.2) and reoperation for instability (0.5 vs 0.5 vs 0.8%, P=0.6), did not statistically differ between cohorts. CONCLUSION/CONCLUSIONS:Selective DM utilization did not reduce 90-day readmissions or reoperations following primary THA. Other dislocation-mitigation strategies (i.e., surgical approach, computer navigation, robotic assistance, and large diameter fixed-bearings) may have masked any benefits of selective DM use.

BACKGROUND:Indications for surgery may impact resource utilization in aseptic revision total knee arthroplasty (rTKA), and understanding these relationships would facilitate risk-stratification preoperatively. The purpose of this study was to investigate the impact of rTKA indications on readmission, reoperation, length of stay (LOS), and cost. METHODS:We reviewed all 962 patients who underwent aseptic rTKA at an academic orthopedic specialty hospital between June 2011-April 2020 with at least 90 days of follow-up. Patients were categorized based on their indication for aseptic rTKA as listed in the operative report. Demographics, surgical factors, LOS, readmission, reoperation and cost were compared between cohorts. RESULTS:There were significant differences in operative time among cohorts (p < 0.001), highest among the periprosthetic fracture group (164.2 ± 59.8 min). Reoperation rate was greatest in the extensor mechanism disruption cohort (50.0 %, p = 0.009). Total cost differed significantly among groups (p < 0.001), which was highest among the implant failure cohort (134.6 % of mean) and lowest for component malpositioning cohort (90.2 % of mean). Similarly, there were significant differences in direct cost (p < 0.001) which was highest in the periprosthetic fracture cohort (138.5 % of mean), and lowest in the implant failure cohort (90.5 % of mean). There were no differences in discharge disposition, or number of re-revisions among all groups. CONCLUSIONS:Operative time, components revised, LOS, readmissions, reoperation rate, total cost and direct cost following aseptic rTKA varied significantly between different revision indications. These differences should be noted for preoperative planning, resource allocation, scheduling, and risk-stratification. LEVEL OF EVIDENCE/METHODS:III, retrospective observational analysis.

BACKGROUND:Patients undergoing total knee arthroplasty (TKA) are at increased risk of venous thromboembolism (VTE). Aspirin has been shown to be effective at reducing rates of VTE. In select patients, more potent thromboprophylaxis is indicated, which has been associated with increased rates of bleeding and wound complications. This study aimed to evaluate the effect of thromboprophylaxis choice on rates of early prosthetic joint infection (PJI) following TKA. METHODS:A review of 11,547 primary TKA patients from 2013 to 2019 at a single academic orthopaedic hospital was conducted. The primary outcome measure was PJI within 90 days of surgery as measured by Musculoskeletal Infection Society criteria. There were 59 (0.5%) patients diagnosed with early PJI. Chi-square and Welch-Two Sample t-tests were used to determine statistically significant relationships between thromboprophylaxis and demographic variables. Significance was set at p<0.05. Multivariate logistic regression adjusted for age, body mass index, sex, and Charlson comorbidity index was performed to identify and control for independent risk factors for early PJI. RESULTS:There was a statistically significant difference in the rates of early PJI between the aspirin and non-aspirin group (0.3 vs 0.8%, p<0.001). Multivariate logistic regressions revealed that patients given aspirin thromboprophylaxis had significantly lower odds of PJI (odds ratios (OR)=0.51, 95% Confidence Interval (CI) 0.29 to 0.89, p=0.019) compared to non-aspirin patients. CONCLUSIONS:The use of aspirin thromboprophylaxis following primary TKA is independently associated with a lower rate of early PJIs. Arthroplasty surgeons should consider aspirin as the gold standard thromboprophylaxis in all patients in which it is deemed medically appropriate and should carefully weigh the morbidity of PJI in patients when non-aspirin thromboprophylaxis is considered.

INTRODUCTION/BACKGROUND:Increasing age and hip fractures are considered risk factors for post-operative complications in total hip arthroplasty (THA). Consequently, older adults undergoing THA due to hip fracture may have different outcomes and require additional healthcare resources than younger patients. This study aimed to identify the influence of age on discharge disposition and 90-day outcomes of THA performed for hip fractures in patients ≥ 80 years to those aged < 80. MATERIALS AND METHODS/METHODS:A retrospective review of 344 patients who underwent primary THA for hip fracture from 2011 to 2021 was conducted. Patients ≥ 80 years old were propensity-matched to a control group < 80 years old. Patient demographics, length of stay (LOS), discharge disposition, and 90-day post-operative outcomes were collected and assessed using Chi-square and independent sample t tests. RESULTS:A total of 110 patients remained for matched comparison after propensity matching, and the average age in the younger cohort (YC, n = 55) was 67.69 ± 10.48, while the average age in the older cohort (OC, n = 55) was 85.12 ± 4.77 (p ≤ 0.001). Discharge disposition differed between the cohorts (p = 0.005), with the YC being more likely to be discharged home (52.7% vs. 27.3%) or to an acute rehabilitation center (23.6% vs. 16.4%) and less likely to be discharged to a skilled nursing facility (21.8% vs. 54.5%). 90-day revision (3.6% vs. 1.8%; p = 0.558), 90-day readmission (10.9% vs. 14.5%; p = 0.567), 90-day complications (p = 0.626), and 90-day mortality rates (1.8% vs 1.8%; p = 1.000) did not differ significantly between cohorts. CONCLUSION/CONCLUSIONS:While older patients were more likely to require a higher level of post-hospital care, outcomes and perioperative complication rates were not significantly different compared to a younger patient cohort. Payors need to consider patients' age in future payment models, as discharge disposition comprises a large percentage of post-discharge expenses. LEVEL OF EVIDENCE/METHODS:Level III, Retrospective Cohort Study.

Purpose/UNASSIGNED:Use of dual mobility (DM) articulations can reduce the risk of instability in both primary and revision total hip arthroplasty (THA). Knowledge regarding the impact of this design on patient-reported outcome measures (PROMs) is limited. This study aims to compare clinical outcomes between DM and fixed bearing (FB) prostheses following primary THA. Materials and Methods/UNASSIGNED:All patients who underwent primary THA between 2011-2021 were reviewed retrospectively. Patients were separated into three cohorts: FB vs monoblock-D vs modular-DM. An evaluation of PROMs including HOOS, JR, and FJS-12, as well as discharge-disposition, 90-day readmissions, and revisions rates was performed. Propensity-score matching was performed to limit significant demographic differences, while ANOVA and chi-squared test were used for comparison of outcomes. Results/UNASSIGNED:=0.608) between the groups. Conclusion/UNASSIGNED:DM bearings yield PROMs similar to those of FB implants in patients undergoing primary THA. Although DM implants are utilized more often in patients at higher-risk for instability, we suggest that similar patient satisfaction may be attained while achieving similar dislocation rates.

BACKGROUND:Although several techniques and implants have been developed to address bone loss in revision total knee arthroplasty (rTKA), management of these defects remains challenging. This review article discusses the indications and management options of bone loss following total knee arthroplasty based on preoperative workup and intraoperative findings. MAIN TEXT/METHODS:Various imaging modalities are available that can be augmented with intraoperative examination to provide a clear classification of a bony defect. For this reason, the Anderson Orthopaedic Research Institute (AORI) classification is frequently used to guide treatment. The AORI provides a reliable system by which surgeons can classify lesions based on their size and involvement of surrounding structures. AORI type I defects are managed with cement with or without screws as well as impaction bone grafting. For AORI type IIA lesions, wedge or block augmentation is available. For large defects encompassing AORI type IIB and type III defects, bulk allografts, cones, sleeves, and megaprostheses can be used in conjunction with intramedullary stems. CONCLUSIONS:Treatment of bone loss in rTKA continues to evolve as different techniques and approaches have been validated through short- and mid-term follow-up. Extensive preoperative planning with imaging, accurate intraoperative evaluation of the bone loss, and comprehensive understanding of all the implant options available for the bone loss are paramount to success.

INTRODUCTION/BACKGROUND:Surgeons can improve their practice by understanding potentially avoidable reasons for early revision total knee arthroplasty (rTKA). The purpose of this study is to describe potentially avoidable indications for rTKA within 5 years of the index procedure. METHODS:This retrospective observational analysis utilized the rTKA database at a large, academic orthopedic specialty hospital to identify 167 consecutive rTKA from 2014 to 2019 performed within 5 years after primary TKA (pTKA). Two fellowship-trained arthroplasty surgeons reviewed the cases to classify them as potentially avoidable or unavoidable. Unavoidable indications for rTKA included infection/wound complication, arthrofibrosis, instability due to underlying collagen disease or significant weight loss, and any traumatic event leading to pTKA failure. Potentially avoidable indications included atraumatic instability, intraoperative fracture, metal allergy, and atraumatic patellar instability or maltracking. Aseptic loosening was considered avoidable if it occurred in the presence of component malpositioning or poor cementation technique. RESULTS:There were 112 (67.1%) unavoidable cases and 55 avoidable cases (32.9%). Of the unavoidable cases, there were 68 rTKA for infection or wound complications (60.7%), 23 for arthrofibrosis (20.5%), 6 for instability (5.4%), 6 for postoperative fracture (5.4%), 6 for aseptic loosening (5.4%), and 3 for extensor mechanism pathology following trauma (2.6%). Of the potentially avoidable rTKA, 24 were for aseptic loosening (43.7%), 23 for atraumatic instability (41.8%), 6 for atraumatic extensor mechanism pathology (10.9%), 1 for nickel allergy (1.8%), and 1 for intraoperative fracture (1.8%). CONCLUSION/CONCLUSIONS:These findings indicate that over 30% of early rTKA are potentially avoidable. Interventions should focus on addressing potentially avoidable causes such as short-term aseptic loosening and instability to reduce the need for costly and resource-intensive rTKA. Level of evidence III, retrospective observational analysis.

INTRODUCTION:Obstructive sleep apnea (OSA) is a known risk factor for venous thromboembolism (VTE), defined as pulmonary embolism (PE) or deep vein thrombosis (DVT); however, little is known about its effect on VTE rates after total joint arthroplasty (TJA). This study sought to determine whether patients with OSA who undergo TJA are at greater risk for developing VTE versus those without OSA. METHODS:A retrospective analysis was conducted on 12,963 consecutive primary TJA patients at a single institution from 2016 to 2019. Patient demographic data were collected through query of the electronic medical record, and patients with a previous history of OSA and VTE within a 90-day postoperative period were captured using the International Classification of Disease, 10th revision diagnosis and procedure codes. RESULTS:Nine hundred thirty-five patients with OSA were identified. PE (0.6% versus 0.24%, P = 0.023) and DVT (0.1% versus 0.04%, P = 0.37) rates were greater for patients with OSA. A multivariate logistic regression revealed that patients with OSA had a higher odds of PE (odds ratio [OR] 3.821, P = 0.023), but not DVT (OR 1.971, P = 0.563) when accounting for significant demographic differences. Female sex and total knee arthroplasty were also associated with a higher odds of PE (OR 3.453 for sex, P = 0.05; OR 3.243 for surgery type, P = 0.041), but not DVT (OR 2.042 for sex, P = 0.534; OR 1.941 for surgery type, P = 0.565). CONCLUSION:Female patients with OSA may be at greater risk for VTE, specifically PE, after total knee arthroplasty. More attention toward screening procedures, perioperative monitoring protocols, and VTE prophylaxis may be warranted in populations at risk.

INTRODUCTION/BACKGROUND:Medicaid expansion has allowed more patients to undergo total hip arthroplasty (THA). Given the continued focus on the opioid epidemic, we sought to determine whether patients with Medicaid insurance differed in their postoperative pain and narcotic requirements compared with privately or Medicare-insured patients. METHODS:A single-institution database was used to identify adult patients who underwent elective THA between 2016 and 2019. Patients in the Medicaid group received Medicaid insurance, while the non-Medicaid group was insured commercially or through Medicare. Subgroup analysis was done, separating the private pay from Medicare patients. RESULTS:A total of 5,845 cases were identified: 326 Medicaid (5.6%) and 5,519 non-Medicaid (94.4%). Two thousand six hundred thirty-five of the non-Medicaid group were insured by private payors. Medicaid patients were younger (56.1 versus 63.28 versus 57.4 years; P < 0.001, P < 0.05), less likely to be White (39.1% versus 78.2% versus 76.2%; P < 0.001), and more likely to be active smokers (21.6% versus 8.8% versus 10.5%; P < 0.001). Surgical time (113 versus 96 versus 98 mins; P < 0.001) and length of stay (2.7 versus 1.7 versus 1.4 days; P < 0.001) were longer for Medicaid patients, with lower home discharge (86.5% versus 91.8% versus 97.2%; P < 0.001). Total opioid consumption (178 morphine milligram equivalents [MMEs] versus 89 MME versus 82 MME; P < 0.001) and average MME/day in the first 24 hours and 24 to 48 hours (52.3 versus 44.7 versus 44.45; P < 0.001 and 73.8 versus 28.4 versus 29.8; P < 0.001) were higher for Medicaid patients. This paralleled higher pain scores (2.71 versus 2.31 versus 2.38; P < 0.001) and lower Activity Measure for Post-Acute Care scores (18.77 versus 20.98 versus 21.61; P < 0.001). CONCLUSIONS:Medicaid patients presenting for THA demonstrated worse postoperative pain and required more opioids than their non-Medicaid counterparts. This highlights the need for preoperative counseling and optimization in this at-risk population. These patients may benefit from multidisciplinary intervention to ensure that pain is controlled while mitigating the risk of continuation to long-term opioid use.